Impeller for electric blower

ABSTRACT

Embodiments of the invention provide an impeller for an electric blower. The impeller includes a hub and a shroud disposed to correspond to the hub so that an internal space and an outlet are formed between the hub and the shroud and including an inlet formed therein to introduce air and a disk part formed from the inlet toward an outside. The impeller further includes a blade disposed in the internal space between the shroud and the hub, whereby a distance from a leading edge of the blade positioned at the inlet side to the center of the inlet is the same as a minimum distance from a rim of the inlet to the center of the inlet.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of and priority under 35 U.S.C. §119to Korean Patent Application No. KR 10-2013-0091127, entitled “IMPELLERFOR ELECTRIC BLOWER,” filed on Jul. 31, 2013, which is herebyincorporated by reference in its entirety into this application.

BACKGROUND

1. Field of the Invention

The present invention relates to an impeller for an electric blower.

2. Description of the Related Art

A conventional impeller has been described in Korean Patent ApplicationNos. KR 10-2004-0082111 (“KR '111”) and KR 10-2005-0014536 (“KR '536”).According to KR '111 and KR '536, the impeller has been generally calleda blowing fan and has been mounted in a cleaner motor and has been usedto suck air.

The conventional impeller, as described in these two documents, isconfigured to include a shroud having an inlet, a hub disposed tocorrespond to the shroud with an internal space disposed therebetween,and having a shaft hole formed at the center thereof so that a shaft iscoupled thereto, and a plurality of blades radially disposed in theinternal space and curved in a length direction, respectively.

According to KR '111 and KR '536, when the conventional impeller rotatestogether with the shaft, the air is sucked through the inlet formed inthe shroud, is guided by the respective blades, is radially dispersed,and is then forwarded outwardly.

Meanwhile, as one of factors deteriorating performance of theconventional impeller, there is a delamination phenomenon of the shroudby a flow generated at the inlet formed in the shroud. As several causesof the delamination phenomenon, there are insufficient guidance of aflow by the blades, a rapid change in a channel area.

Generally, a leading edge of the conventional impeller is formed so thata point at which the shroud and the blade meet each other and a point atwhich the blade and the hub meet each other is connected to each otherin a straight line form, similar to the conventional impeller describedin KR '111, or is formed so that they are connected to each other in acurved line form, similar to the conventional impeller described in KR'536, and the blade has a height equal to or higher than that of adistal end of the impeller. In addition, a distance from the center C ofthe impeller to the blade is larger than a radius of the inlet.

Thus, since a radius from the center of the conventional impeller to apoint at which the blade and the shroud meet each other is larger thanthat of the inlet, a space in which air introduced through the inlet ofthe conventional impeller is not guided by the blade is formed, and thedelamination phenomenon occurs in this space.

In addition, a ratio between an inlet area of the conventional impellerand an inlet area of the blade obtained by rotating a straight linevertically connected from a point at which the blade meets the shroud tothe hub by 360 degrees is excessively large, the flow rapidly decreasesto increase the delamination phenomenon of the shroud by the flow.

In the conventional impeller according to KR '111 and KR '536, sinceonly a curvature of a point at which the shroud and the blade meet eachother is managed as a design factor, there is a limitation in decreasingthe delamination phenomenon of the entire shroud generated by the flow,which hinders improvement of performance of the electric blower.

SUMMARY

Accordingly, embodiments of the invention have been made to solve theabove-mentioned problems, and therefore provide an impeller for anelectric blower capable of improving suction force and efficiency of theelectric blower by solving a delamination phenomenon between a blade anda shroud, which is a problem according to the conventional art, forexample, KR '111 and KR '536.

Further, embodiments of the invention have been made in an effort toprovide an impeller for an electric blower capable of easily improvingsuction force and efficiency of the electric blower by improving a bladeand a shroud.

According to an embodiment of the invention, there is provided animpeller for an electric blower, including a hub, a shroud disposed tocorrespond to the hub so that an internal space and an outlet are formedbetween the hub and the shroud and including an inlet formed therein tointroduce air and a disk part formed from the inlet toward an outside,and a blade disposed in the internal space between the shroud and thehub. A distance from a leading edge of the blade positioned at the inletside to the center of the inlet is the same as a minimum distance from arim of the inlet to the center of the inlet.

According to an embodiment, a ratio between a height of the leading edgeof the blade positioned at the inlet side and a height of a trailingedge of the blade positioned at the outlet side is 2.4 to 2.6.

According to an embodiment, a ratio between a diameter of the outlet anda diameter of the inlet is 2.2 to 2.4.

According to an embodiment, a ratio between an area formed by rotatingthe leading edge of the blade based on the center of the inlet by 360degrees and an area of the inlet is 1.4 to 1.5.

According to another embodiment of the invention, there is provided animpeller for an electric blower, including a hub, a shroud disposed tocorrespond to the hub so that an internal space and an outlet are formedbetween the hub and the shroud and including an inlet formed therein tointroduce air and a disk part rounded in a shape of an oval curved linefrom the inlet toward an outside, and a blade disposed in the internalspace between the shroud and the hub.

According to an embodiment, the center of a curvature of the disk partis formed to be the same as a height at which a leading edge of theblade is connected to the shroud.

According to an embodiment, a ratio between a height of the leading edgeof the blade positioned at the inlet side and a height of a trailingedge of the blade positioned at the outlet side is 2.4 to 2.6.

According to an embodiment, a ratio between a diameter of the outlet anda diameter of the inlet is 2.2 to 2.4.

According to an embodiment, a ratio between an area formed by rotatingthe leading edge of the blade based on the center of the inlet by 360degrees and an area of the inlet is 1.4 to 1.5.

According to an embodiment, a distance from a leading edge of the bladepositioned at the inlet side to the center of the inlet is the same as adistance from a rim of the inlet to the center of the inlet.

According to another embodiment of the invention, there is provided animpeller for an electric blower, including a hub, a shroud disposed tocorrespond to the hub so that an internal space and an outlet are formedbetween the hub and the shroud and including an inlet formed therein tointroduce air and a disk part formed from the inlet toward an outside,and a blade disposed in the internal space between the shroud and thehub. A distance from a leading edge of the blade positioned at the inletside to the center of the inlet is smaller than a distance from an outerdiameter of the inlet to the center of the inlet.

According to an embodiment, an upper surface of the blade that the airfirst contacts is inclined at an angle of 0 to 5 degrees in upward anddownward directions based on the inlet.

According to an embodiment, a straight line formed at the leading edgeof the blade toward the shroud is inclined at an angle of 0 to 5 degreesin forward and backward directions.

According to an embodiment, a ratio between a diameter of the outlet anda diameter of the inlet is 2.2 to 2.4.

According to an embodiment, a ratio between a height of the leading edgeof the blade positioned at the inlet side and a height of a trailingedge of the blade positioned at the outlet side is 2.4 to 2.6.

According to an embodiment, a ratio between an area formed by rotatingthe leading edge of the blade based on the center of the inlet by 360degrees and an area of the inlet is 1.4 to 1.5.

According to an embodiment, the disk part is rounded in a shape of anoval curved line from the inlet toward an outside.

According to an embodiment, the center of a curvature of the disk partis formed to be the same as a height at which a leading edge of theblade is connected to the shroud.

Various objects, advantages and features of the invention will becomeapparent from the following description of embodiments with reference tothe accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

These and other features, aspects, and advantages of the invention arebetter understood with regard to the following Detailed Description,appended Claims, and accompanying Figures. It is to be noted, however,that the Figures illustrate only various embodiments of the inventionand are therefore not to be considered limiting of the invention's scopeas it may include other effective embodiments as well.

FIG. 1 is a schematic view showing an impeller for an electric bloweraccording to an embodiment of the invention.

FIG. 2 is a cross-sectional view showing the impeller for an electricblower according to an embodiment of the invention.

FIG. 3 is a partially cut-away perspective view of the impeller for anelectric blower according to an embodiment of the invention.

FIG. 4 is an exploded perspective view showing a state in which theimpeller for an electric blower according to an embodiment of theinvention is installed.

FIG. 5 is a schematic view showing an impeller for an electric bloweraccording to an embodiment of the invention.

FIG. 6 is a cross-sectional view showing the impeller for an electricblower according to another embodiment of the invention.

FIG. 7 is a partially cut-away perspective view of the impeller for anelectric blower according to another embodiment of the invention.

FIG. 8 is an exploded perspective view showing a state in which theimpeller for an electric blower according to another embodiment of theinvention is installed.

FIGS. 9 to 11 are schematic views showing an impeller for an electricblower according to another embodiment of the invention.

FIG. 12 is a cross-sectional view showing the impeller for an electricblower according to another embodiment of the invention.

FIG. 13 is a partially cut-away perspective view of the impeller for anelectric blower according to another embodiment of the invention.

FIG. 14 is an exploded perspective view showing a state in which theimpeller for an electric blower according to another embodiment of theinvention is installed.

DETAILED DESCRIPTION

Advantages and features of the present invention and methods ofaccomplishing the same will be apparent by referring to embodimentsdescribed below in detail in connection with the accompanying drawings.However, the present invention is not limited to the embodimentsdisclosed below and may be implemented in various different forms. Theembodiments are provided only for completing the disclosure of thepresent invention and for fully representing the scope of the presentinvention to those skilled in the art.

For simplicity and clarity of illustration, the drawing figuresillustrate the general manner of construction, and descriptions anddetails of well-known features and techniques may be omitted to avoidunnecessarily obscuring the discussion of the described embodiments ofthe invention. Additionally, elements in the drawing figures are notnecessarily drawn to scale. For example, the dimensions of some of theelements in the figures may be exaggerated relative to other elements tohelp improve understanding of embodiments of the present invention. Likereference numerals refer to like elements throughout the specification.

Hereinafter, various embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings.

In an impeller for an electric blower according to various embodimentsof the invention, a distance from a leading edge of a blade to thecenter of an inlet through which the air is introduced is equal to aminimum distance from an outer diameter of the inlet to the centerthereof in order to prevent a delamination phenomenon due to formationof a space in which the introduced air is not guided by the blade.

According to an embodiment, the blades are radially disposed in aninternal space formed by a hub coupled to a shaft of a cleaner motor anda shroud provided with the inlet through which the air is introduced todisperse the air introduced through the inlet. In addition, therespective blades are curved in a length direction at a uniformcurvature.

According to an embodiment, the hub, which is coupled to the shaft ofthe cleaner motor described above to rotate together with the cleanermotor when the cleaner motor rotates, has a hole formed at a centralportion thereof to be coupled to the shaft. In addition, the shroud isdisposed to correspond to the hub so that an internal space in which theblades are disposed and an outlet through which the air is dischargedare formed in the impeller.

According to an embodiment, the shroud and the hub are connected to eachother by the blade. As an example, a plurality of slits are formed ineach of the shroud and the hub, protrudes inserted into the slits areformed on the blades, and the blades are coupled to the shroud and thehub through the protrusions and the slits and are then fixed thereto bya method such as a caulking method, at an outer portion of the impeller.

Meanwhile, the impeller for an electric blower according to anembodiment of the invention is mounted and used in a scheme in which thehub is coupled to the shaft of the cleaner motor, as described above.Here, the cleaner motor will be schematically described below.

According to an embodiment, the cleaner motor is a switched reluctancemotor (SRM) in which both of cores of a stator and a rotor are formed ina magnetic structure, which is a salient pole, and a concentrated typecoil is wound only around the stator without forming any excitationdevice (a winding or a permanent magnet) in the rotor.

Thus, the switched reluctance motor (SRM), which rotates the rotor usinga reluctance torque depending on a change in magnetic reluctance, has alow manufacturing cost, hardly requires maintenance, and has an almostpermanent lifespan due to high reliability. However, the switchedreluctance motor (SRM) is only an example of the cleaner motor. That is,the cleaner motor is not necessarily limited to the switched reluctancemotor (SRM).

Meanwhile, in the conventional impeller, only a curvature of a portionat which the leading edge of the blade and the shroud are connected toeach other is managed as a design factor. To the contrary, in theimpeller for an electric blower according to various embodiments of theinvention, a curvature of the entire shroud is defined as an oval, suchthat a point of inflection is not present.

According to an embodiment, the center of the curvature of the shroud isformed to be substantially the same as a height at which the leadingedge of the blade is connected to the shroud. Further, the shroud isdivided into two parts: a surface that contacts the blade and a surfacethat does not contact the blade. The surface of the shroud that contactsthe blade is defined using a portion of an oval, and the other surfaceof the shroud is formed as an extension line to prevent a shape of theshroud from being rapidly changed. Therefore, the shroud is improved asdescribed above to prevent a delamination phenomenon of the shroud by aflow.

On the other hand, in the impeller for an electric blower according tovarious embodiments of the invention, a ratio between an inlet area ofthe impeller and an inlet area of the blade formed by rotating astraight line vertically connected from a point at which the blade meetsthe shroud to the hub by 360 degrees is 1.4 to 1.5, such that a rapidchange in a flow area is decreased.

Hereinafter, various embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings.

FIRST EMBODIMENT

As shown in FIGS. 1 to 3, an impeller 100 according to a firstembodiment of the invention includes a blade 130 disposed in an internalspace 110 a formed between a hub 110 and a shroud 120. Therefore, theshroud 120 and the hub 110 are connected to each other through the blade130.

According to an embodiment, the hub 110 has a mounting hole 111 formedat a central portion thereof so that a shaft 13 of a cleaner motor 10 ismounted therein and generally has a disk shape. In addition, the shroud120 includes an inlet 121 formed in a circular shape at a centralportion thereof to introduce air and a disk part 122 formed from theinlet 121 toward an outside.

According to an embodiment, the shroud 120 is disposed over the hub 110to correspond to the hub 110 to form the internal space 110 a and anoutlet 110 b in the impeller 110, and a plurality of blades 130 areradially disposed in the internal space 110 a.

According to an embodiment, the blade 130, which is a kind of strip, iscurved in a length direction. Here, a distance R1 from a leading edgeA-B of the blade 130 positioned at the inlet 121 side formed in theshroud 120 and connecting the shroud 120 and the hub 110 to each otherto the center C of the inlet 121 is the same as a minimum distance RAfrom a rim of the inlet 121 to the center C of the inlet 121.

Thus, as an example, the distance RA from the rim of the inlet 121 tothe center C of the inlet 121 is 51.285 mm, and the distance R1 from theleading edge A-B of the blade 130 to the center C1 of the inlet 121 isalso 51.285 mm.

Therefore, the distance from the leading edge A-B of the blade 130 tothe center C1 of the inlet 121 is the same as the minimum distance fromthe rim of the inlet 121 to the center C of the inlet 121, such that airintroduced through the inlet 121 is directly guided by the leading edgeA-B of the blade 130, thereby preventing a delamination phenomenongenerated in the conventional impeller.

Meanwhile, a ratio (B1:B2) between a height B1 of the leading edge A-Bof the blade 130 positioned at the inlet 121 side and a height B2 of atrailing edge a-b of the blade 130 positioned at the outlet 110 a sideis 2.4 to 2.6. Thus, as an example, a distance B1 of the leading edgeA-B of the blade 130 is 38.01 mm, and a distance B2 of the trailing edgea-b thereof is 15.21 mm.

A ratio (D2:D1) between a diameter D2 of the outlet 110 b and a diameterD1 of the inlet 121 is 2.2 to 2.4. As an example, the diameter D1 of theinlet 121 is 94.88 mm. In addition, the diameter D2 of the outlet 110 bis 217.14 mm.

When an area formed by rotating the leading edge A-B of the blade 130based on the center C of the inlet 121 by 360 degrees is defined as F1and an area of the inlet 121 is defined as F0, a ratio (F1: F0) betweenF1 and F0 is 1.4 to 1.5.

Thus, F0 is defined as πR1², and F1 is defined as 2πRAB1.

As shown in FIG. 4, the cleaner motor 10 includes a stator 11, a rotor12, and a shaft 13 configuring a general switched reluctance motor(SRM), wherein the rotor 12 is rotatably installed in the center of thestator 11 and the shaft 13 is installed at the center of the rotor 12.In addition, the hub 110 is mounted around the shaft 13 through themounting hole 111, such that it rotates when the cleaner motor 10 isdriven.

Therefore, in the impeller 100 according to the first embodiment of theinvention, the air introduced into the internal space 110 a through theinlet 121 when the cleaner motor 10 rotates is guided by the leadingedges A-B of the blades 130, is uniformly dispersed by the respectiveblades 130, and is then discharged finally through the outlet 110 b.

SECOND EMBODIMENT

As shown in FIGS. 5 to 7, an impeller 200 according to a secondembodiment of the invention includes a blade 230 disposed in an internalspace 210 a formed between a hub 210 and a shroud 220. Therefore, theshroud 220 and the hub 210 are connected to each other through the blade230.

According to an embodiment, the hub 210 has a mounting hole 211 formedat a central portion thereof so that a shaft 13 of a cleaner motor 10 ismounted therein and generally has a disk shape. In addition, the shroud220 includes an inlet 221 formed in a circular shape at a centralportion thereof to introduce air and a disk part 222 formed from theinlet 221 toward an outside.

According to an embodiment, the disk part 222 is rounded in a shape ofan oval curved line. A curvature of the disk part 222 contacting theblade 230 is formed as the oval curved line to remove a point ofinflection, thereby preventing a delamination phenomenon of the shroud220 generated by a flow. In addition, the center of the curvature of thedisk part 222 is formed to be substantially the same as a height atwhich a leading edge A of the blade 230 is connected to the shroud 220.

Therefore, the shroud 220 is disposed over the hub 210 to correspond tothe hub 210 to form the internal space 210 a and an outlet 210 b in theimpeller 200 and stabilize a flow of air discharged to the outlet 210 bthrough the internal space 210, thereby preventing the delaminationphenomenon.

According to an embodiment, the blade 230, which is a kind of strip, iscurved in a length direction and is radially disposed in the internalspace 210 a. Here, a distance R1 from a leading edge A-B of the blade230 positioned at the inlet 221 side formed in the shroud 220 andconnecting the shroud 220 and the hub 210 to each other to the center Cof the inlet 221 is the same as a minimum distance RA from a rim of theinlet 221 to the center C of the inlet 221.

For example, the distance RA from the rim of the inlet 221 to the centerC of the inlet 221 is 51.285 mm, and the distance R1 from the leadingedge A-B of the blade 230 to the center C1 of the inlet 221 is also51.285 mm.

Therefore, the distance from the leading edge A-B of the blade 230 tothe center C1 of the inlet 221 is the same as the minimum distance fromthe rim of the inlet 221 to the center C of the inlet 221, such that airintroduced through the inlet 221 is directly guided by the leading edgeA-B of the blade 230, thereby preventing a delamination phenomenongenerated in the impeller according to the prior art.

Meanwhile, a ratio (B1:B2) between a height B1 of the leading edge A-Bof the blade 230 positioned at the inlet 221 side and a height B2 of atrailing edge a-b of the blade 230 positioned at the outlet 210 b sideis 2.4 to 2.6. For example, a distance B1 of the leading edge A-B of theblade 230 is 38.01 mm, and a distance B2 of the trailing edge a-bthereof is 15.21 mm.

According to an embodiment, a ratio (D2:D1) between a diameter D2 of theoutlet 210 b and a diameter D1 of the inlet 221 is 2.2 to 2.4. As anexample, the diameter D1 of the inlet 221 is 94.88 mm,.In addition, thediameter D2 of the outlet 210 b is 21.7.14 mm.

When an area formed by rotating the leading edge A-B of the blade 230based on the center C of the inlet 221 by 360 degrees is defined as F1and an area of the inlet 221 is defined as F0, a ratio (F1:F0) betweenF1 and F0 is 1.4 to 1.5.

Thus, F0 is defined as πR1², and F1 is defined as 2πRAB1.

As shown in FIG. 8, the cleaner motor 10 includes a stator 11, a rotor12, and a shaft 13 configuring a general switched reluctance motor(SRM), wherein the rotor 12 is rotatably installed in the center of thestator 11 and the shaft 13 is installed at the center of the rotor 12.In addition, the hub 210 is mounted around the shaft 13 through themounting hole 211, such that it rotates when the cleaner motor 10 isdriven.

Therefore, in the impeller 200 according to the second embodiment of theinvention, the air introduced into the internal space 210 a through theinlet 221 when the cleaner motor 10 rotates is guided by the leadingedges A-B of the blades 230, is uniformly dispersed by the respectiveblades 230 in a state in which a flow of air is stabilized by the diskpart 222 of the shroud 220, and is then discharged finally through theoutlet 210 b.

THIRD EMBODIMENT

As shown in FIG. 9, an impeller 300 according to a third embodiment ofthe invention includes a blade 330 disposed in an internal space 310 aformed between a hub 310 and a shroud 320. Therefore, the shroud 320 andthe hub 310 are connected o each other through the blade 330.

According to anembodiment, the blade 330, which is a kind of strip, iscurved in a length direction and is radially disposed in the internalspace 310 a. Here, a distance R1 from a leading edge A-B of the blade330 positioned at the inlet 321 side formed in the shroud 320 to thecenter C of the inlet 321 is smaller than a distance RA from a rim ofthe inlet 321 to the center C of the inlet 321.

For example, when the distance RA from the rim of the inlet 321 to thecenter C of the inlet 321 is 51.285 mm, the distance R1 from the leadingedge A-B of the blade 330 to the center C1 of the inlet 321 is smallerthan 51.285 mm. Therefore, the air introduced into the impeller 300through the inlet 321 is guided by the leading edge A-B of the blade330, thereby preventing a delamination phenomenon generated in theimpeller according to the prior art.

As shown in FIGS. 10 and 11, an upper surface 331 of the blade 330 thatthe air introduced through the inlet 321 first contacts is inclinedbased on the inlet 321. As an example, the upper surface 331 is inclinedat an angle of 5 degrees in upward and downward directions.

According to an embodiment, a configuration of the leading edge A-B ofthe blade 330 generally formed at a right angle (90 degrees) to theshroud 320 is improved. As an example, a straight line formed toward theshroud 320 is inclined at an angle of 5 degrees in forward and backwarddirections.

As shown in FIGS. 12 and 13, the hub 310 has a mounting hole 311 formedat a central portion thereof so that a shaft 13 of a cleaner motor 10 ismounted therein and generally has a disk shape. In addition, the shroud320 includes an inlet 321 formed in a circular shape at a centralportion thereof to introduce air and a disk part 322 formed from theinlet 321 toward an outside.

According to an embodiment, the disk part 322 is rounded in a shape ofan oval curved line. A curvature of the disk part 322 contacting theblade 330 is formed as the oval curved line to remove a point ofinflection, thereby preventing a delamination phenomenon of the shroud320 generated by a flow. In addition, the center of the curvature of thedisk part 322 is formed to be substantially the same as a height atwhich a leading edge A of the blade 330 is connected to the shroud 320.

Therefore, the shroud 320 is disposed over the hub 310 so as tocorrespond to the hub 312 to form the internal space 310 a and an outlet310 b in the impeller 300 and stabilize a flow of air discharged to theoutlet 310 b through the internal space 310, thereby preventing thedelamination phenomenon.

Meanwhile, a ratio (B1:B2) between a height B1 of the leading edge A-Bof the blade 330 positioned at the inlet 321 side and a height B2 of atrailing edge a-b of the blade 330 positioned at the outlet 310 b sideis 2.4 to 2.6. For example, a distance B1 of the leading edge A-B of theblade 330 is 38.01 mm, and a distance B2 of the trailing edge a-bthereof is 15.21 mm.

According to an embodiment, a ratio (D2:D1) between a diameter D2 of theoutlet 310 b and a diameter D1 of the inlet 321 is 2.2 to 2.4. Forexample, the diameter D1 of the inlet 321 is 94.88 mm. In addition, thediameter D2 of the outlet 310 b is 217.14 mm.

In addition, when an area formed by rotating the leading edge A-B of theblade 330 based on the center C of the inlet 321 by 360 degrees isdefined as F1 and an area of the inlet 321 is defined as F0, a ratio(F1:F0) between F1 and F0 is 1.4 to 1.5.

Thus, F0 is defined as πR1², and F1 is defined as 2πRAB1.

As shown in FIG, 14, the cleaner motor 10 includes a stator 11, a rotor12, and a shaft 13 configuring a general switched reluctance motor(SRM), wherein the rotor 12 is rotatably installed in the center of thestator 11 and the shaft 13 is installed at the center of the rotor 12.In addition, the hub 310 is mounted around the shaft 13 through themounting hole 311, such that it rotates when the cleaner motor 10 isdriven.

Therefore, in the impeller 300 according to the third embodiment of theinvention, the air introduced into the internal space 310 a through theinlet 321 when the cleaner motor 10 rotates is guided by the leadingedges A-B of the blades 330, is uniformly dispersed by the respectiveblades 330 in a state in which a flow of air is stabilized by the diskpart 322 of the shroud 320, and is then discharged finally through theoutlet 310 b.

According to various embodiments of the invention, the distance from theleading edge of the blade to the center of the inlet is the same as theminimum distance from an outer diameter of the inlet to the center ofthe inlet, such that air introduced through the inlet is guided by theleading edge of the blade, thereby easily preventing a delaminationphenomenon. Therefore, suction force and efficiency of the electricblower may be easily improved.

Meanwhile, according to another embodiment of the invention, the shroudincludes the disk part rounded in a shape of an oval curved line fromthe inlet toward an outside to remove a point of inflection in acurvature of the entire shroud, thereby easily preventing a delaminationphenomenon of the shroud generated by a flow. Therefore, suction forceand efficiency of the electric blower may be easily improved.

On the other hand, according to still another embodiment of theinvention, the distance from the leading edge of the blade to the centerof the inlet is smaller than the distance from an outer diameter of theinlet to the center of the inlet, such that air introduced through theinlet is guided by the leading edge of the blade, thereby easilypreventing a delamination phenomenon. Therefore, suction force andefficiency of the electric blower may be easily improved.

Terms used herein are provided to explain embodiments, not limiting thepresent invention. Throughout this specification, the singular formincludes the plural form unless the context clearly indicates otherwise.When terms “comprises” and/or “comprising” used herein do not precludeexistence and addition of another component, step, operation and/ordevice, in addition to the above-mentioned component, step, operationand/or device.

Embodiments of the present invention may suitably comprise, consist orconsist essentially of the elements disclosed and may be practiced inthe absence of an element not disclosed. For example, it can berecognized by those skilled in the art that certain steps can becombined into a single step.

The terms and words used in the present specification and claims shouldnot be interpreted as being limited to typical meanings or dictionarydefinitions, but should be interpreted as having meanings and conceptsrelevant to the technical scope of the present invention based on therule according to which an inventor can appropriately define the conceptof the term to describe the best method he or she knows for carrying outthe invention.

The terms “first,” “second,” “third,” “fourth,” and the like in thedescription and in the claims, if any, are used for distinguishingbetween similar elements and not necessarily for describing a particularsequential or chronological order. It is to be understood that the termsso used are interchangeable under appropriate circumstances such thatthe embodiments of the invention described herein are, for example,capable of operation in sequences other than those illustrated orotherwise described herein. Similarly, if a method is described hereinas comprising a series of steps, the order of such steps as presentedherein is not necessarily the only order in which such steps may beperformed, and certain of the stated steps may possibly be omittedand/or certain other steps not described herein may possibly be added tothe method.

The singular forms “a,” “an,” and “the” include plural referents, unlessthe context clearly dictates otherwise.

As used herein and in the appended claims, the words “comprise,” “has,”and “include” and all grammatical variations thereof are each intendedto have an open, non-limiting meaning that does not exclude additionalelements or steps.

As used herein, the terms “left,” “right,” “front,” “back,” “top,”“bottom,” “over,” “under,” and the like in the description and in theclaims, if any, are used for descriptive purposes and not necessarilyfor describing permanent relative positions. It is to be understood thatthe terms so used are interchangeable under appropriate circumstancessuch that the embodiments of the invention described herein are, forexample, capable of operation in other orientations than thoseillustrated or otherwise described herein. The term “coupled,” as usedherein, is defined as directly or indirectly connected in an electricalor non-electrical manner. Objects described herein as being “adjacentto” each other may be in physical contact with each other, in closeproximity to each other, or in the same general region or area as eachother, as appropriate for the context in which the phrase is used.Occurrences of the phrase “according to an embodiment” herein do notnecessarily all refer to the same embodiment.

Ranges may be expressed herein as from about one particular value,and/or to about another particular value. When such a range isexpressed, it is to be understood that another embodiment is from theone particular value and/or to the other particular value, along withall combinations within said range.

Although the present invention has been described in detail, it shouldbe understood that various changes, substitutions, and alterations canbe made hereupon without departing from the principle and scope of theinvention. Accordingly, the scope of the present invention should bedetermined by the following claims and their appropriate legalequivalents.

What is claimed is:
 1. An impeller for an electric blower, comprising: ahub; a shroud disposed to correspond to the hub so that an internalspace and an outlet are formed between the hub and the shroud andincluding an inlet formed therein to introduce air and a disk partformed from the inlet toward an outside; and a blade disposed in theinternal space between the shroud and the hub, wherein a distance from aleading edge of the blade positioned at the inlet side to the center ofthe inlet is the same as a minimum distance from a rim of the inlet tothe center of the inlet.
 2. The impeller for the electric blower as setforth in claim 1, wherein a ratio between a height of the leading edgeof the blade positioned at the inlet side and a height of a trailingedge of the blade positioned at the outlet side is 2.4 to 2.6.
 3. Theimpeller for the electric blower as set forth in claim 1, wherein aratio between a diameter of the outlet and a diameter of the inlet is2.2 to 2.4.
 4. The impeller for the electric blower as set forth inclaim 1, wherein a ratio between an area formed by rotating the leadingedge of the blade based on the center of the inlet by 360 degrees and anarea of the inlet is 1.4 to 1.5.
 5. An impeller for an electric blower,comprising: a hub; a shroud disposed to correspond to the hub so that aninternal space and an outlet are formed between the hub and the shroudand including an inlet formed therein to introduce air and a disk partrounded in a shape of an oval curved line from the inlet toward anoutside; and a blade disposed in the internal space between the shroudand the hub.
 6. The impeller for the electric blower as set forth inclaim 5, wherein a center of a curvature of the disk part is formed tobe the same as a height at which a leading edge of the blade isconnected to the shroud.
 7. The impeller for the electric blower as setforth in claim 5, wherein a ratio between a diameter of the outlet and adiameter of the inlet is 2.2 to 2.4.
 8. The impeller for the electricblower as set forth in claim 5, wherein a ratio between a height of theleading edge of the blade positioned at the inlet side and a height of atrailing edge of the blade positioned at the outlet side is 2.4 to 2.6.9. The impeller for the electric blower as set forth in claim 5, whereina ratio between an area formed by rotating the leading edge of the bladebased on the center of the inlet by 360 degrees and an area of the inletis 1.4 to 1.5.
 10. The impeller for the electric blower as set forth inclaim 5, wherein a distance from a leading edge of the blade positionedat the inlet side to the center of the inlet is the same as a minimumdistance from a rim of the inlet to the center of the inlet.
 11. Animpeller for an electric blower, comprising: a hub; a shroud disposed tocorrespond to the hub so that an internal space and an outlet are formedbetween the hub and the shroud and including an inlet formed therein tointroduce air and a disk part formed from the inlet toward an outside;and a blade disposed in the internal space between the shroud and thehub, wherein a distance from a leading edge of the blade positioned atthe inlet side to the center of the inlet is smaller than a distancefrom an outer diameter of the inlet to the center of the inlet.
 12. Theimpeller for the electric blower as set forth in claim 11, wherein anupper surface of the blade that the air first contacts is inclined at anangle of 0 to 5 degrees in upward and downward directions based on theinlet.
 13. The impeller for the electric blower as set forth in claim11, wherein a straight line formed at the leading edge of the bladetoward the shroud is inclined at an angle of 0 to 5 degrees in forwardand backward directions.
 14. The impeller for the electric blower as setforth in claim 11, wherein a ratio between a diameter of the outlet anda diameter of the inlet is 2.2 to 2.4.
 15. The impeller for the electricblower as set forth in claim 11, wherein a ratio between a height of theleading edge of the blade positioned at the inlet side and a height of atrailing edge of the blade positioned at the outlet side is 2.4 to 2.6.16. The impeller for the electric blower as set forth in claim 11,wherein a ratio between an area formed by rotating the leading edge ofthe blade based on the center of the inlet by 360 degrees and an area ofthe inlet is 1.4 to 1.5.
 17. The impeller for the electric blower as setforth in claim 11, wherein the disk part is rounded in a shape of anoval curved line from the inlet toward an outside.
 18. The impeller forthe electric blower as set forth in claim 17, wherein a center of acurvature of the disk part is formed to be the same as a height at whicha leading edge of the blade is connected to the shroud.